[Synthesis, crystal structure and luminescent properties of a dysprosium coordinaation polymer based on pyridine-2, 6-dicarboxylic acid].

2-D layered Dy coordination polymer [Dy(PDA) (HPDA)I]n (1)(H2PDA = pyridine-2,6-dicarboxylic acid) with (4.8(2)) topological network was synthesized under hydrothermal conditions and was characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. X-ray diffraction analysis reveals that compound 1 is monoclinic, space group P2(1)/c. In the structure of compound 1, metal-centered Dy is connected via O atoms of H2PDA ligands to form a (4.82) topology network. The 3-D supramolecular structure of 1 is constructed through pi--pi stacking interactions between the adjacent layers. The luminescence properties of 1 were determined by UV-Vis and fluorescence spectrum in solid state at room temperature. The H2PDA and 1 exhibit the similar broad maximum absorption peak at 280 nm, which are attributed to ligand-centered pi--pi* transition. The fluorescence emission band based on ligand-center and characteristic emission of Dy3+ at the same maximum excitation wavelength of 280 nm were observed in 1. The fluorescence decay curve of complex 1 indicated that the processes of decay consists of two components, of which corresponding lifetimes tau1 = 3.61 micros and tau2 = 12.81 micros.